Shoeprints Presentation
Guillermo Basulto-Elias
Shoeprints Data Collection
A Question of Interest
- Footwear impressions are common in crime scenes
- Was this shoeprint left by this particular shoeprint?
Questions About the Crime Scene Print
- Can we determine brand, model or size? These are class characteristics
- Can we find scratches, cuts or other marks? These are individual characteristics
- The individual characteristics are also known as randomly acquired characteristics (RACs)
Some challenges
- Overlayed prints
- Obstacles created by the substrate
- Potential problems while casting (e.g., on dirt or snow) or lifting shoeprints evidence
Why do we need a shoeprints database?
- What are reliable and accurate methods to quantify the similarity between two outsole prints?
- How robust are those methods to degradation of the crime scene print?
- What is the best instrument to measure outsole images? (We are using at least five different instruments).
- What is the persistence of outsole patterns over time? Or, can we identify the source of a print even after the shoe has been used for period of weeks or months?
Details
- Provide a pair of shoes to 160 persons (ISU students, staff, faculty and external)
- Roughly half men and half women
- Half one shoe pattern and half the other
- Take measurements every six weeks (baseline + four times)
Shoe models
- Contrained to:
- current and future availability
- One athletic and one more casual
- Nike Winflow 4 (left)
- Adidas Seeley (right)
Restrictions for impressions
- Time it takes to take each impression
- Adapt to schoolyear dates
- Tidiness of the space
3D Scans
2D Scans
High Resolution Picture
- Modes: 2 (different lighting)
- Format: TIFF
